Vista reactivation after imaging..?

I have seen a number of posts on other Forums where some members are reporting reactivation issues with Vista. There are some reports that if you Clone / Image the Vista disk / partition to another physical disk that when you want to boot from the Cloned disk / Imaged partition, Vista asks for reactivation.

I have done some investigation of this potential issue on the Microsoft site and my understanding is that in the initial design Microsoft had included a reactivation requirement if the system disk ID changed. However, as a result of user-pressure this requirement was dropped from the final release and that the reactivation requirements of Vista are identical to those of XP.

Can Forum members ....

a) Advise if they have noted any issues around reactivation when changing the physical disk

b) Confirm (or not) if the reactivation requirements of Vista are the same as those of XP